Handheld surgical instrument

ABSTRACT

A handheld surgical instrument comprising an energy storage element, wherein the energy storage element is a spring coupled to the impacting mechanism, an impacting mechanism has a tip configured to impact a bone, wherein the tip includes a tapered point, a power transmission mechanism is configured to transmit energy from the energy storage element to the impacting mechanism, wherein the power transmission mechanism includes a semi-flexible metal wire guided by a hollow shaft, wherein the hollow shaft includes a distal end, the semi-flexible metal wire is includes a bend toward the distal end, a trigger mechanism is configured to release energy from the energy storage element, wherein the bend includes an angle between 14 degrees and 46 degrees, wherein the trigger mechanism includes a manual lever which, when actuated, simultaneously retracts the tip and charges the energy storage element.

CLAIM OF PRIORITY

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/464,614 filed Feb. 28, 2017 and U.S. Provisional PatentApplication Ser. No. 62/596,420 filed Dec. 8, 2017, both of which areherein incorporated by reference.

FIELD OF THE INVENTION

The present invention is generally directed to a device for surgery, andmore particularly, for accessing bone marrow for enhancement of tissuerepair. One popular example use is performing automated microfracture onsubchondral bone to repair articular cartilage. Other examples includethe stimulation of healing in areas of tendinosis such as elbow lateralepicondylitis, patella tendinopathy, hip gluteus medius tendinopathy,and ankle achilles tendinitis; to stimulate ligament healing such as inknee medial collateral ligament sprains; to enhance soft tissue to bonehealing such as in the repair of the shoulder rotator cuff tendon tobone; for the enhancement of bony healing in fractures; and in thepreparation of bone for improved healing to prosthetic implants.

DESCRIPTION OF THE RELATED ART

Bone marrow and its associated cells are known to have regenerativeproperties which makes it valuable medicinally in areas of wear, damage,or impairment. In many cases, soft tissue and bone healing can benefitfrom improved access to bone marrow, typically through small holes inbone. One area of benefit is in articular cartilage repair. Articularcartilage is a smooth, low-friction tissue which covers the ends ofbones and enables healthy joint function. Articular cartilage is proneto damage from excessive wear or traumatic injuries, as are common insports. When articular cartilage is damaged, it can result in pain andreduced mobility for the patient, and in some cases subsequentarthritis. Articular cartilage has extremely limited ability to repairitself spontaneously due to absent blood flow. Microfracture surgeryexists as a method to assist in the repair of articular cartilage inorder to improve joint function. Microfracture creates a pathway forcartilage-building cells in blood and bone marrow to travel from theunderlying cancellous bone to the articular surface by producing smallholes in the cortical bone. Microfracture procedures are typicallyperformed using an awl or a pick that is hit with a hammer.

Other conditions where healing is often limited or impaired occurs indegenerative conditions where soft tissue attaches to bone, such as inrotator cuff tears and various insertional tendinopathies such as elbowlateral epicondylitis, patella tendinopathy, and Achilles tendinitis. Inthese situations, there is again limited or absent blood flow, andtherefore healing is impaired without access to the necessary cells andgrowth factors. Drilling or perforation of the bone is performed toallow bone marrow and blood to access the area of damage. Similarly, incases of delayed or absent fracture healing, or in the preparation ofsurfaces for bone to implant healing, drill holes are often made toallow bone marrow and blood to reach the area of relatively poorcirculation.

Some marrow access devices, for example U.S. Pat. No. 9,510,840 (“the'840 patent), are utilized via driving a wire with a hammer through anangled cannula. Like the hammer and awl method, this method requires aminimum of three hands to operate, and delivers inconsistent results dueto its subjective and uncontrolled external force delivery, which is aproblem in microfracture procedures. Furthermore, the awl-like designand its associated user experience of applying aggressive, torsional,radial and axial force to remove the tip can result in tips breaking asdocumented in FDA MAUDE reports 3004154314-2013-00007,3004154314-2013-00009, 3004154314-2016-00015, and several others, whichare incorporated by reference. While a removal tab is claimed in the'840 patent, insufficient mechanical advantage and poor user experiencedesign leads operators to resort to excessive lateral and axial force,such as hitting the tab with a hammer and/or aggressively shimmying itback and forth, delivering treacherous stresses to the bone plate andthe penetrator, weakening both and compacting the sides of the channel.

Some automated microfracture devices have been introduced which rely onexternal power sources such as compressed air or specialty electricalpower supplies. This presents a challenge as many surgical facilitiesare without access to said power sources.

SUMMARY

Reported clinical results of microfracture are very good in some cases,but other researchers have reported relatively poorer results. Part ofthis may be related to the variability of the manually performedtechnique. To improve effectiveness during procedures, active surgeonfeedback such as good visibility is of prime importance. Many marrowaccess procedures are performed arthroscopically. Operating a surgicalscope (arthroscope) requires focus, precision, and a steady hand, andthe coordination of meticulous hole creation relies upon such control.Therefore the primary operator is often inclined to maintain control ofthe scope. This leaves the primary operator's other hand available forone of two tasks: Hold the awl, or swing the hammer. Both of theserequire equal or higher levels of finesse to operate effectively, andare interdependent from one another and from the scope.

To date, the typical method of performing microfracture involves holdinga longitudinal awl with an angled tip, and a hammer for impacting theproximal end of the handle of said awl. At the same time, a surgicalscope must be held and positioned in a manner which allows the surgeonto see the tip alignment, the depth of penetration, and the subsequentblood flow from each hole produced. As such, a problem exists in that atleast three hands are required to perform such a procedure using thehistorically accepted method. While each tool must be operated withcareful precision, and the feedback from each tool is interdependent,coordinating a microfracture procedure with a minimum of two operatorspresents a challenge.

There are several technical challenges associated with the creation ofmicrofracture holes in the bone. The depth of penetration must besufficient to adequately access the bone marrow elements underneath therelatively avascular subchondral bone. The holes must be of sufficientwidth to allow bone marrow and blood to reach the surface of the bone,while not being so large as to significantly affect the load-bearingcharacteristics of the bone. Holes must be adequately spaced apart toallow for adequate flow to cover the surface, but not collapse into eachother. Ideally, the holes should be perpendicular to the surface so thatminimal tissue is perforated to allow access to the bone surface.

The standard technique uses a hammer manually impacting the back end ofthe awl. This can result in a highly variable amount of force beingapplied, resulting in unpredictable hole size and depth. In addition,excessive load can cause significant bone edema, pain and loss offunction in patients.

Furthermore, the direction of force applied by the hammer is notsubstantially aligned with the orientation of the tip, and the tip maynot be perpendicular to the bone surface. This often results insubstantial undesired damage to the subchondral bone, since an obliquehole or trough may be created. In many cases, the lateral forcetransmitted to the awl tip causes the tip to break into an adjacenthole, significantly disrupting the subchondral bone. In other cases, theindividual holes created may be much wider than what is necessary,leading to complications and prolonged recovery time.

There are also multiple awl types, sizes, and tip designs. Many of thesedesigns have very thick and robust tips to withstand the obliquelyapplied hammering force, but this can create issues with size of holecreation. In addition, the majority of these instruments aremultiple-use, and tend to dull or blunt over time, resulting in a needfor increased force application to create the holes.

Another example application of the present invention is to improveaccess to bone marrow and blood to enhance soft tissue or bony healing,including fracture union, fusion, or healing to prosthetic implants.Insufficient access to bone marrow in said procedures can result inreduced progenitor cells and growth factors, and ultimately substandardclinical outcomes. Currently, this access is achieved either with theuse of an awl, with the previously described deficiencies; or bydrilling into the bone. Drilling of the bone has several limitations:typically, this is performed through an open and not minimally invasivesurgical technique. The angle of drilling is usually limited by use of astraight drill bit. Larger holes can weaken the underlying bony tissue,while smaller drill bits are prone to breakage due to the often awkwardpositioning and unbalanced size of the power drill. Drilling has alsobeen implicated in thermal necrosis (death) of the bone, which iscounterproductive in the healing environment. This can be exacerbated bythe typical reuse of many drill bits which become duller with continueduse. Finally, drilling with the typical size drill and bit is usually atwo handed procedure requiring an assistant to retract adjacent tissue.

The present invention introduces a novel instrument for use inmicrofracture procedures and other bone marrow access procedures whichsolves the multiple issues mentioned above. The novel instrument can beoperated using one hand, emulating both the hammer and the awl of thehistorically accepted microfracture procedure, or the stabilized drilland bit. In such form, one operator may coordinate each essentialsurgical element simultaneously with precision. Additionally, the devicecan have variable angles to access the bone, unlike a straight awl ordrill bit. The present invention demonstrates a means of transmittingpower to a force in a direction better aligned with the orientation ofthe tip. This device can deliver a precise load and direction to thetip, resulting in much better controlled hole size, shape, and depth.Another advantage is a disposable tip, which can also increase theaverage sharpness of the instrument when used. The present inventioncomprises a one-handed solution for creating holes in tissue. Theinstrument comprises six main parts, including a master energy storageelement (1100); an impact mechanism (1200); a power transmissionmechanism (1300); a tip (1400); a means of energy input (1500); and atrigger mechanism (1600). Two or more of these parts may be combined,for example in a direct drive configuration, whereby the impactmechanism, the power transmission mechanism, and the tip are allconnected.

In one embodiment of the present invention, the handheld surgicalinstrument (1000) comprises a flat spring (1150) as a master energystorage element (1100); an impacting drive mechanism utilizing a linearspring (1230); a power transmission mechanism (1300); an elongated shaftcomprising a distal end and a proximal end, and angled at 30 degrees; atip with a proximal end (1410), which may be engaged by the powertransmission mechanism and a distal end (1420) with a sharpened point(1421) for engaging the subchondral bone; a means of energy input by theuser (1500); and a trigger mechanism (1600) to initiate impact.

In another embodiment of the present invention, the handheld surgicalinstrument (1000) comprises a compressed fluid cylinder (1110) as themaster energy storage element (1100); an impacting drive mechanism(1200) powered directly by the master energy storage element (1240); apower transmission mechanism (1300); an elongated shaft comprising adistal end and a proximal end, and angled at 90 degrees; a tip (1400)with a proximal end (1410), which may be engaged by the powertransmission mechanism (1411) and a distal end (1420) with a drill point(1423) for engaging the subchondral bone; a means of energy input by theuser (1500); and a trigger mechanism (1600) to initiate impact.

In another embodiment of the present invention, the handheld surgicalinstrument (1000) houses a direct-drive carriage, which is connected tothe power transmission mechanism (1300) and to the tip (1400), togetherforming the impact mechanism (1200). In this embodiment, the proximalend of the tip and the semi-flexible wire within the bent shaft, that isthe power transmission mechanism, are one in the same.

In one embodiment of the present invention, the entire device isdisposable, so as to ensure a safe and sterile procedure administered bythe device. In another embodiment, the tip is removable, and can becleaned by standard reprocessing methods.

In yet another embodiment, the present invention includes a handheldsurgical instrument having an energy storage element, wherein the energystorage element is a spring coupled to the impacting mechanism, theimpacting mechanism having a tip configured to impact a bone, whereinthe tip includes a tapered point, a power transmission mechanism isconfigured to transmit energy from the energy storage element to theimpacting mechanism, wherein the power transmission mechanism includes asemi-flexible metal wire guided by a hollow shaft, wherein the hollowshaft includes a distal end, wherein the semi-flexible metal wire isincludes a bend toward the distal end. A trigger mechanism is configuredto release energy from the energy storage element, wherein the bendincludes an angle between 14 degrees and 46 degrees, wherein the triggermechanism includes a manual lever which, when actuated, simultaneouslyretracts the tip and charges the energy storage element.

In an alternative embodiment, the invention includes a method ofperforming surgery that includes the use of a handheld surgicalinstrument comprising an energy storage element, wherein the energystorage element is a spring coupled to the impacting mechanism. Animpacting mechanism has a tip configured to impact a bone, wherein thetip includes a tapered point. A power transmission mechanism isconfigured to transmit energy from the energy storage element to theimpacting mechanism, wherein the power transmission mechanism includes asemi-flexible metal wire guided by a hollow shaft, wherein the hollowshaft includes a distal end. The semi-flexible metal wire is includes abend toward the distal end. A trigger mechanism is configured to releaseenergy from the energy storage element, wherein the bend includes anangle between 14 degrees and 46 degrees, wherein the trigger mechanismincludes a manual lever which, when actuated, simultaneously retractsthe tip and charges the energy storage element.

These and various other characteristics are pointed out withparticularity in the claims annexed hereto and form a part hereof.Reference should also be made to the drawings which form a further parthereof, and to accompanying descriptive matter, in which there areillustrated and described representative examples of systems,apparatuses, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

The elements and workings of the present invention can be betterunderstood by taking into account the underlying detailed description ofthe invention in conjunction with the definitions listed below. Elementsare labeled numerically and hierarchically to help the reader betterunderstand individual references and their inherent relationships. Likenumbers refer to like parts and furthermore;

(1XXX.) refers to any part or feature of the instrument;

(11XX.) refers to any part or feature of the instrument relatingdirectly to the master energy storage element;

(12XX.) refers to any part or feature of the instrument relatingdirectly to the impact mechanism;

(13XX.) refers to any part or feature of the instrument relatingdirectly to the power transmission mechanism;

(14XX.) refers to any part or feature of the instrument relatingdirectly to the tip;

(15XX.) refers to any part or feature of the instrument relatingdirectly to the means of energy input;

(16XX.) refers to any part or feature of the instrument relatingdirectly to the trigger mechanism.

(2XXX.) refers to anatomical structures in microfracture procedures;

(21XX.) refers to cartilage tissue;

(22XX.) refers to subchondral bone tissue;

(23XX.) refers to openings created by microfracture procedures;

(24XX.) refers to cancellous bone;

(3XXX.) refers to the orientation and the direction of force applied tothe tip;

(31XX.) refers to the tip geometry which interacts with the tissue;

(32XX.) refers to the angle of the tip with respect to the surface ofthe subchondral bone plate.

FIG. 1 is a block diagram of the Device (1000).

FIG. 2 is a block diagram of the Master Energy Storage Element (1100).

FIG. 3 is a block diagram of the Impact Mechanism (1200).

FIG. 4 is a block diagram of the Power Transmission Mechanism (1300).

FIG. 5 is a block diagram of the Tip (1400).

FIG. 6 is a block diagram of the Means of Energy Input (1500).

FIG. 7 is a block diagram of the Trigger (1600).

FIG. 8 is a block diagram of of the Device in an alternate embodiment(1000 a).

FIG. 9 is an assembled view of one possible embodiment of the Device(1000).

FIG. 10 is a representation of an alternate embodiment of the Device(1000).

FIG. 11 is an assembled view of one possible embodiment of the MasterEnergy Storage Element (1100).

FIG. 12 is an assembled view of one possible embodiment of the ImpactMechanism (1200).

FIG. 13 is an assembled view of one possible embodiment of the PowerTransmission Mechanism (1300).

FIG. 14 is an assembled view of one possible embodiment of the Tip(1400).

FIG. 15 illustrates a variety of different holes that could be createdby a microfracture procedure.

FIG. 16 illustrates the effect of ‘skiving’ in microfracture due to themisalignment of the tip, the force vector, and the subchondral boneplate (3000).

FIG. 17 is a block diagram of the Device (1000) in one embodiment.

FIG. 18 illustrates possible retraction and charging or energy input ofthe Device (1000).

FIG. 19 illustrates an example of optional secondary Energy InputMechanism (1500).

FIG. 20 illustrates an example of the Tip (1400) interacting with thePower Transmission Mechanism (1300).

FIG. 21 illustrates an example Trigger Mechanism (1600) embodiment andits interface with the Power Transmission Mechanism (1300).

FIG. 22 is an orthographic view of one possible Trigger Mechanism (1600)embodiment.

FIG. 23 illustrates an example embodiment of the depth indicator.

FIG. 24 illustrates an alternative or dynamic orientation of the shaft,transmission mechanism and tip.

FIG. 25 illustrates an example of the Device in use on a patient in anopen and in an arthroscopic procedure.

FIG. 26 illustrates a cross-sectional view of one embodiment of theDevice.

FIG. 27 illustrates an example kit in which a plurality of TransmissionMechanisms and Tips of varying geometry are provided.

FIG. 28 illustrates an example embodiment of the Device in fullydisposable form.

In the figures, like reference numerals designate like elements.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingdrawings that form a part hereof, and in which is shown by way ofillustration various embodiments in which the invention may bepracticed. It is to be understood that other embodiments may beutilized, as structural and operational changes may be made withoutdeparting from the scope of the present invention. The followingdetailed description, therefore, is not to be taken in a limiting sense,and the scope of the invention is defined by the appended claims.

The present invention comprises a handheld surgical instrument forcreating holes in tissue. The instrument comprises six main parts,including a master energy storage element (1100); an impact mechanism(1200); a power transmission mechanism (1300); a tip (1400); a means ofenergy input (1500); and a trigger mechanism (1600).

In one embodiment, the master energy storage element (1100) is a flatcoil spring wound around two cylinders, one cylinder being the “storagedrum”, and the other being the “output drum”. By way of example and notlimitation, this flat spring could be Vulcan Spring SV12J192. Whenassembled in an arrangement where the center of the output drum is fixedat a particular distance from the center of the storage drum—2.60 inchesin this case—the winding of the spring around the two drums can resultin a torque curve that is nearly constant as the spring length travelsfrom the output drum to the storage drum. The flat coil spring in thisassembly shall be referred to as a “constant torque spring”. In thisexample, the resulting torque is approximately 7.50 in-lbs. Thisresulting torque can be applied to various mechanisms within the device.In one embodiment, the output drum is fixed to a shaft which is alsoattached to a ratcheting mechanism. By way of example and notlimitation, the means of energy input (1500) could be achieved through asliding handle which the user may operate to engage the ratcheting gear,rotating the output shaft, transferring the length of the flat coilspring to the output drum and “charging” the constant torque springmaster energy storage element. In one embodiment, the torque from theflat spring is used to charge the impact mechanism (1200) with a rackand pinion arrangement. The ratcheting pawl may be disengaged from theratcheting gear by a user-operated lever, freeing the constant torquespring to do work. By way of example and not limitation, the piniongear, a 14.5 degree pressure angle, 20 tooth spur gear with a 0.625 inchpitch diameter (McMaster 6867K553), is fixed to a shaft which is alsofixed to the output drum. In this example, the pinion may engage with afitting rack in order to compress a linear compression spring. By way ofexample and not limitation, the linear compression spring could be a2.50 inch long stainless steel spring with a spring constant of 16.90lbs/inch which compresses to 1.33 inches (McMaster 1986K19). In thisexample, the linear spring produces 19.773 lbs of force when fullycompressed. With the specified constant torque spring and the specifiedpinion gear in this example, a total force of 24 lbs can be applied tothe rack and subsequently, the linear compression spring—enough to fullycompress said spring. In this example, the rack has a slot which is usedconstrain it to sliding only, whereas the coupler of a parallel four barmechanism is mated with the slot, and can be used to change the heightof the slot with respect to the pinion, engaging or disengaging the rackwith the pinion. In this example, the trigger (1600) is attached to theparallel four bar mechanism. Once the linear compression spring is fullycompressed, the trigger can be used to disengage the rack from thepinion gear, “firing” a metal carriage which acts as an impacting massfor energy transfer. The impacting mass engages the power transmissionmechanism (1300). By way of example and not limitation, the powertransmission mechanism may consist of a stainless steel rod inside astainless steel shaft on one side, and a plurality of tightly tolerancedstainless steel balls, as a clearance fit, inside the other end of theshaft, which is optionally bent. In this example the rod is held flushagainst the balls by an extension spring mated to the rod and when theimpacting mass impacts the rod, energy is transferred through the ballsto the tip, conserving momentum and providing output energy to the tip(1400). By way of example and not limitation, the tip may include asharpened metal body with a blunt proximal end for engaging thedistalmost stainless steel ball of the power transmission mechanism. Inthis example the tip is constrained axially to the shaft but not rigidlyfixed to said shaft. In this example, a small light compression springis used as a buffer between the sharpened body and the shaft so that themajority of energy from the impacting drive mechanism may be applied tothe sharpened tip body without the additional inertia of the shaft. Theresult is that the sharpened tip may engage the subchondral bone withmajority axial force, driving to a sufficient depth and not producingany unnecessary damage to the subchondral bone.

In one embodiment, the device exists as an attachment which can combinewith existing tools as a means of providing an energy input, a handle,and/or a trigger. FIG. 8 illustrates one possibility of how the blockdiagram in FIG. 1 could be “short-circuited” or plugged into anotherdevice.

In another embodiment, the Means of Energy Input is a lever attached tothe handle. Operating this lever could progressively charge the EnergyStorage Element. The Impact Mechanism could optionally be triggered oncethe charge lever reaches a predetermined position. The Impact Mechanismcould optionally be triggered by the user at any position, giving theuser added control in the amount of force transmitted by the ImpactMechanism. The charge lever could optionally include a ratchetingmechanism for multiple operations by the user before triggering.

The master energy storage element (1100) enables the device to storesufficient energy to match the requirement for the creation of two ormore holes. The master energy storage element may include some means ofengagement (1170) with the power transmission (1300) and/or the impactmechanism. The master energy storage element may exist, by way ofexample and not limitation, in one of the following forms; a compressedfluid chamber (1110); a chemically-based battery (1120); a mechanicalflywheel (1130); a hydraulic reservoir (1140); a flat spring (1150); alinear spring (1160).

The impact mechanism provides a means by which to apply a force toultimately be transmitted to the tip for the creation of one or moreholes. The impact mechanism may be charged (1210) by the master energystorage element (1100); and may also utilize a mechanism for thereduction of recoil (1220) on the user. The impact mechanism isoptionally driven by a secondary energy storage element (1230). In oneembodiment, the impact mechanism is driven directly by the master energystorage element (1240). In one embodiment, the impact mechanism providesa force to the power transmission mechanism (1300). In one embodiment,the device includes a damper (1250) to soften the residual impactdelivered by the impact mechanism.

The power transmission mechanism (1300) receives energy input from theimpact mechanism (1320) or the master energy storage element; andprovides a means by which to transmit power and provide output energy tothe tip (1330); optionally utilizing one or more springs as a buffer orfor position restoration (1340). The power transmission mechanismoptionally transfers the direction of force (1310) applied by the impactmechanism. In one embodiment, the power transmission mechanism transfersthe direction of force by 30 degrees. In another embodiment, the powertransmission mechanism transfers the direction of force by 90 degrees.The power transmission mechanism is optionally enclosed in a flexible orbendable housing, and constructed in such a manner to allow forcorresponding freedom of form (1350). The power transmission mechanismoptionally utilizes one or more spherical bodies within a smooth,constrained pathway for the facilitation of efficient energy transfer(1360).

The tip (1400) optionally exists as an assembly comprising of one ormore springs (1430) to provide a buffer between attached bodies or forrepositioning and comprises a proximal end (1410), which may be engagedby the power transmission mechanism; and a distal end (1420), optionallywith a sharpened point (1421); optionally comprising one or more wires(1422); optionally with a chisel or drill-like geometry (1423);optionally comprising a multitude of impact points (1424). The tipoptionally has a diameter of 1 millimeter or less in order to limitexcessive damage to the subchondral bone, while still providing thenecessary blood flow access for cartilage regeneration.

The means of energy input (1500) allows a user to add energy to thedevices energy storage elements for the subsequent utilization ofinternal mechanisms. The means of energy input is optionally handoperated (1510); the means of energy input is optionally performedutilizing non-human external assistance (1520).

If by manual user operation, in one embodiment, the means of energyinput is detachable (1511). In another embodiment, the means of energyinput is a rotatable crank lever (1512). In one embodiment, the means ofenergy input is a sliding handle (1513).

If by way of non-human external assistance, the means of energy inputcould be in the form of fluid power (1521) or an electromechanicalsystem (1522).

The trigger mechanism (1600) provides a way to initiate mechanisms forthe subsequent creation of holes in tissue and may interact with anyother part in the device (1000) such as the impact mechanism (1640) orthe master energy storage element (1650). The interface between theimpact mechanism and the trigger mechanism optionally includes multipledetents (1641) to enable a ratcheting effect during energy input. Thetrigger mechanism optionally comprises of one or more safety lockingmechanisms (1610) and is optionally a double set trigger, or optionallya progressive or staged trigger (1630). One embodiment of the safetymechanism is a pin (1611) that, when displaced in a particulardirection, interferes with the firing operation of the trigger. Anotherembodiment of a safety mechanism is a separate track and body (1612)which together only allow firing of the trigger when the device is in aparticular state.

In one embodiment of the device, the impact mechanism, the transmissionmechanism, and the tip are all connected to each other so as toaccelerate the tip directly, without relying primarily on impactproximally within the device. In this embodiment, the transmissionmechanism may exist as a semi-flexible element (1351) such as a steel,nitinol, or titanium wire, which can traverse a bend in the shaft (1352)without failure. The drive carriage may be charged, triggered, and firedusing a spring (1160) capable of storing enough energy to penetratedense human tissue or bone. The drive carriage may be partially or fullydecoupled from the handle body at the moment of impact by allowing thespring to accelerate the impact carriage and tip before impacting thetissue; Such configuration reduces device kick-back in the direction ofthe operator on impact. Additionally, the handle body may include addedweight for increased inertia and resulting decreased acceleration in thedirection of the operator. The energy storage element (1100) maytransfer energy for part of, or most of, the stroke of the direct drivecarriage so as to reduce recoil or kick-back on the operator. It hasbeen discovered that, with a sharpened surgical stainless steel tip of1.0 mm diameter, a kinetic energy of greater than 0.7 joules at themoment of impact results in sufficient depth of penetration (6-8 mm) in30# bone foam substrate, which closely resembles subchondral bone plate.In one embodiment, the direct drive carriage is attached to a bundle ofwires that make up the tip or several tips for simultaneous orsequential impact.

Device may include a feature enabling the impacting tip (1400) toretract, or move proximally relative to the shaft, utilizing sufficientleverage to pull the tip out of the tissue after impacting. Thisleverage may be applied with one or more of the following, including butnot limited to a screw, a cam, a roller, a slider crank, a pull wire, orsome combination thereof. FIG. 18 shows one example of this utilizing acam and a roller (1514). In one embodiment, this leverage is appliedusing the same hand that triggers the impact by way of a lever. In oneembodiment, this leverage is applied using a second hand. In oneembodiment, this mechanism is assisted by a spring. Retraction mechanismoptionally utilizes a ratcheting or indexing mechanism, preventingpremature triggering and/or enabling the user to operate retractionlever more than once so that sufficient mechanical advantage and strokeare attainable.

Device may include an element enabling the visualization of impactpositioning before triggering impact. In one embodiment, this featureexists as a stop point in the stroke of the tip (1425), such as thatenabled by a locking pawl. In doing so, the operator may do a portionof, or a majority of drive carriage charging before placing in position,reducing the stability disturbance and alignment challenge whilecharging, and also exhibiting precise placement of the impacting tip. Inone embodiment, the visualization element exists as a separate body fromthe impacting tip. In this embodiment, the visualization element couldattach to the primary drive wire by means of element including but notlimited to a wire, a spring, a channel or other body. In one embodiment,the visualization element is a laser. In one embodiment, thevisualization element is a focused stream of fluid.

Device optionally features a depth indicator on the handle body or shaftto show relative or absolute depth of penetration into the tissue. Inone embodiment, this indicator exists as a marker on the drive carriage(1201), viewable through an opening in the side of the handle body, forwhich the distance from the marker to the end of the tip is constant atthe moment after impact. This depth indicator optionally features afinite set of two or more result indicators (1202), for example and notlimitation, a binary indicator to indicate sufficient depth or notsufficient depth, or a scaled indicator to indicate what range orpercentile of depth penetration was achieved. This feature is optionallyembodied by an infinite relative position indicator window which may ormay not have guiding markings on it. In one embodiment, the markings onthe indicator depict a typical range of thicknesses of cortical bone, toassist the operator in conceptualizing the resulting impact depth.

The device may be assembled, packaged, and shipped with the main energystorage element completely uncharged, or partially uncharged. In such anembodiment, the user may prime the device when it is ready for use byintroducing initial single operation energy input. In doing so at thisstage as opposed to upon assembly of the device and before storage ofthe device reduces possibility of creep, wear, and deformation. The actof priming the device may also serve as a means to communicate to theuser that the device is now ready for use and should be handled as such.In one embodiment, the means of delivering initial energy input to primethe device is a rotational cam (1515) that interfaces with one end of aspring. A leveraging element for priming may be attached to or shippedwith the device.

The semi-flexible drive element and/or the shaft may be produced orprocessed in such a way to yield an interface or multiple interfaceswith low coefficients of friction. This may be done with a smooth orlubricious coating such as a PTFE or EPTFE or biocompatible lubricant.This may be achieved with a metal impregnated with a biocompatiblelubricant. This may be achieved with a surface treatment to bare wiresuch as polishing, plating or lapping. Internal friction may be reducedby reducing the total surface area in contact between the inside of theshaft and the outside of the drive element, such as one or moresurrounding collars applying the pressure instead of solely the innerwall of the cannula or shaft applying pressure.

The shaft or cannula may feature a non-uniform axial profile (1441) inorder to optimize one or more of the following: stiffness,accessibility, control, and/or visualization. In one embodiment, this isdone with two or more nested tubes of different diameters, optionallywelded for rigidity.

In one embodiment, this is done with a single shaft, stepped and/orgradually tapered down its length. In one embodiment, the distal tip ofthe shaft or cannula has a sharp edge (1442), whether straight, jagged,segmented or otherwise. This sharp edge could be on the interiordiameter, outer diameter, or both.

The device optionally includes a mechanism (1311) allowing the shaft orcannula to rotate on its primary axis, improving control and ergonomicfunctionality by modifying the direction of impact relative to theoperator's hand. In one embodiment, this mechanism exists as two or morefinite positions of angular displacement. In one embodiment, thismechanism exists as a joint of infinite angular positioning. In oneembodiment, this articulation can be actively controlled with the samehand that holds the device. In one embodiment, this articulation isperformed using a second hand. The device may be made available withseveral different tip angles, optionally packaged and sold together in akit. The device may be packaged and sold with a tool and or instructionfor the operator to bend the tip before use to their desired position.

The foregoing description of the example embodiments has been presentedfor the purposes of illustration and description. It is not intended tobe exhaustive or to limit the invention to the precise form disclosed.Many modifications and variations are possible in light of the aboveteaching. It is intended that the scope of the invention be limited notwith this detailed description, but rather determined by the claimsappended hereto.

Although specific embodiments have been illustrated and described hereinfor purposes of description of the preferred embodiment, it will beappreciated by those of ordinary skill in the art that a wide variety ofalternate and/or equivalent implementations calculated to achieve thesame purposes may be substituted for the specific embodiments shown anddescribed without departing from the scope of the present invention.Those with skill in the mechanical, electro-mechanical, and electricalarts will readily appreciate that the present invention may beimplemented in a very wide variety of embodiments. This application isintended to cover any adaptations or variations of the preferredembodiments discussed herein. Therefore, it is manifestly intended thatthis invention be limited only by the claims and the equivalentsthereof.

1. A handheld surgical instrument comprising: An energy storage element;An impacting mechanism having a tip configured to impact a bone; A powertransmission mechanism configured to transmit energy from the energystorage element to the impacting mechanism; A trigger mechanismconfigured to release energy from the energy storage element.
 2. Theinstrument of claim 1 wherein the energy storage element is a springcoupled to the impacting mechanism.
 3. The instrument of claim 2,wherein the power transmission mechanism includes a semi-flexible metalwire guided by a hollow shaft.
 4. The instrument of claim 3, wherein thehollow shaft includes a distal end, wherein the semi-flexible metal wireis includes a bend toward the distal end.
 5. The instrument of claim 4,wherein the bend includes an angle between 14 degrees and 46 degrees. 6.The instrument of claim 5, wherein the tip includes a tapered point ofsaid metal wire.
 7. The instrument of claim 6, wherein the triggermechanism includes a manual lever which, when actuated, simultaneouslyretracts the tip and charges the energy storage element.
 8. Theinstrument of claim 7, wherein the trigger mechanism includes a lockingmechanism configured to enable a user to control and apply a moment tothe instrument when in operation.
 9. The instrument of claim 1, furthercomprising a transmission mechanism comprised of a plurality of rigidbodies positioned within a guiding shaft, wherein the transmissionmechanism is located distally from the impacting mechanism, andproximally from the tip.
 10. The instrument of claim 3, wherein thesteel wire is heat treated
 11. The instrument of claim 1 wherein theenergy storage element is a battery.
 12. The instrument of claim 2,wherein the spring is configured to store enough energy to cause the tipto impact the bone multiple times.
 13. The instrument of claim 1,wherein the impacting mechanism includes a carriage configured totransfer energy from the energy storage element to the tip, whereby amajority of energy from the energy storage element is used to acceleratethe tip before the tip impacts the bone, thereby reducing recoil. 14.The instrument of claim 3, wherein the shaft is tapered.
 15. Theinstrument of claim 3, wherein the shaft is rotatable.
 16. Theinstrument of claim 1, further comprising a one-time pre-loading cam.17. The instrument of claim 1, further comprising biologics fortherapeutic use.
 18. The instrument of claim 1, further comprising adepth indicator for measuring the distance the tip penetrates the bone.19. A handheld surgical instrument comprising: An energy storageelement, wherein the energy storage element is a spring coupled to theimpacting mechanism; An impacting mechanism having a tip configured toimpact a bone, wherein the tip includes a tapered point; A powertransmission mechanism configured to transmit energy from the energystorage element to the impacting mechanism, wherein the powertransmission mechanism includes a semi-flexible metal wire guided by ahollow shaft, wherein the hollow shaft includes a distal end, whereinthe semi-flexible metal wire is includes a bend toward the distal end; Atrigger mechanism configured to release energy from the energy storageelement, wherein the bend includes an angle between 14 degrees and 46degrees, wherein the trigger mechanism includes a manual lever which,when actuated, simultaneously retracts the tip and charges the energystorage element.
 20. A method of performing surgery, comprising: Using ahandheld surgical instrument comprising an energy storage element,wherein the energy storage element is a spring coupled to the impactingmechanism; An impacting mechanism having a tip configured to impact abone, wherein the tip includes a tapered point; A power transmissionmechanism configured to transmit energy from the energy storage elementto the impacting mechanism, wherein the power transmission mechanismincludes a semi-flexible metal wire guided by a hollow shaft, whereinthe hollow shaft includes a distal end, wherein the semi-flexible metalwire is includes a bend toward the distal end; A trigger mechanismconfigured to release energy from the energy storage element, whereinthe bend includes an angle between 14 degrees and 46 degrees, whereinthe trigger mechanism includes a manual lever which, when actuated,simultaneously retracts the tip and charges the energy storage element.